My first and most earnest acknowledgment must go to my advisor and chair Ph.D committee. I joined University of Southern California graduate school and started my research work at the impact lab nearly four and half years ago. The deepest thanks go to my wonderful parents who cultivate and educate me with their endless love. My final and and most heartfelt acknowledgment must go to my lovely wife. Her support, encouragement and companionship have turned my study and research journey into a pleasure.